Heating device

ABSTRACT

A device for heating a flowing medium (e.g., water), wherein the device comprises a heating module and a heat exchanger enclosed by an insulating material comprising a vacuum-packed core material. The heating module and the heat exchanger may further be received in a housing having a number of walls, wherein the vacuum-packed core material is arranged between one of the walls and the heating module and/or the heat exchanger.

The invention relates to a device for heating a flowing medium such aswater, comprising a heating module and a heat exchanger connectedthereto which are at least partially enclosed by an insulating material.Such a heating device is generally known, for instance in the form of acentral heating boiler. Such a CH boiler is marketed by applicant indifferent variants under the names Kompakt HRE and Prestige HR.

In a CH boiler water is heated and then transported via conduits toradiators in a space in order to heat this space. The heating modulegenerally comprises a gas burner for the purpose of heating the water.In a so-called combi-boiler tap water is also heated in addition towater for heating. Use is made here of a heat exchanger so that the heatof the gas burner can be transferred via one of the media to the othermedium without the liquid flows coming into direct contact with eachother.

A “heating device” is understood in the present application to mean anyappliance suitable for heating a medium which is used to heat a space orsuitable for heating tap water. In addition to central heatingboilers—both combi-boilers and solo boilers—this is thus also understoodto mean hot water appliances for tap water. Heating devices of the abovedescribed type must meet increasingly higher standards in respect of theefficiency to be achieved thereby. This is related to the wish to makebuildings, and particularly dwellings, increasingly energy-efficient. Inorder to specify the energy efficiency of a building use is made of anindex, the so-called Energy Performance Coefficient (EPC). A maximumvalue has been specified for this EPC, which is continuously beinglowered. From 2006 a maximum EPC of 0.8 thus applied to house buildingin the Netherlands, but since 2011 this may amount to only 0.6. Theexpectation is that from 2015 the EPC norm will even be set at 0.4. TheEnergy Performance Coefficient of a dwelling is calculated on the basisof the energy consumption associated with use of the building. This isunderstood to mean the energy necessary to heat or cool the indoorclimate, for the hot tap water and lighting. The efficiency of theheating boiler is therefore of great importance for the level of theEnergy

Performance Coefficient, particularly in the case of a combi-boiler.

The energy consumption over a 24-hour cycle of use is taken into accountfor the purpose of calculating the EPC. The standstill losses thenbecome a significant factor for a heating boiler.

The invention now has for its object to provide a heating device of theabove described type which has a high energy efficiency and thereforehas a favourable effect on the EPC of a dwelling in which it is applied.

This is achieved according to the invention in such a heating device inthat the insulating material comprises a vacuum-packed core material.Such a vacuum-packed core material has a heat conduction coefficientwhich is much lower than that of conventional insulating materials andamounts to no more than 0.005 W/mK. A much thinner layer of material canthereby be applied in order to achieve the same insulation. Thethickness of the layer of vacuum-packed core material need in practiceamount to only about an eighth of the thickness of a layer ofconventional insulating material with the same insulating properties.The vacuum-packed core material used as insulating material can herebybe much lighter than conventional insulating materials, whereby it isalso easier to process. The vacuum-packed core material moreovercomprises no fibres, this in contrast to many conventional insulatingmaterials. This is important with a view to working conditionslegislation.

If the heating module and the heat exchanger are received in a housingwith a number of walls, the vacuum-packed core material is preferablyarranged between at least one of the walls and the heating module and/orthe heat exchanger.

A structurally simple embodiment of the heating device according to theinvention is then obtained when the vacuum-packed core material isembodied as a panel, and such a vacuum panel is arranged along at leastone of the walls.

The vacuum panel is preferably arranged along a substantially closedwall of the housing. It is not therefore necessary to break through thepanel for passage of conduits and the like, whereby it can bemanufactured in relatively simple manner as an integral unit.

In order to prevent overheating of the vacuum-packed core material, itis recommended that this material is arranged at a distance from theheating module and/or the heat exchanger.

This can be achieved in structurally simple manner when the heatingdevice is provided with at least one spacer arranged between the heatingmodule and/or the heat exchanger on the one side and the at least onevacuum panel on the other.

When the at least one vacuum panel comprises a reflective foil enclosingthe core material, it is recommended that the at least one spacer issubstantially permeable to radiation. The thermal radiation coming fromthe heating module and/or the heat exchanger can then be reflected bythe foil without the spacer (s) forming an obstruction here.

This effect can be achieved with simple means when the at least onespacer comprises a plate with a number of openings.

It is on the other hand also possible to envisage the heating moduleand/or the heat exchanger being fixed with bolts to a wall of thehousing and the at least one spacer comprising a bush or ring arrangedround at least one of the bolts. A desired distance between the heatingmodule/heat exchanger and the vacuum panel can thus also be ensured insimple manner.

The invention will now be elucidated on the basis of two embodiments,wherein reference is made to the accompanying drawing, in which:

FIG. 1 is a perspective view with exploded parts of a part of a heatingdevice according to a first embodiment of the invention,

FIG. 2 shows a cross-section through the vacuum panel along line II-IIin FIG. 1, and

FIG. 3 is a view corresponding to FIG. 1 of an alternative embodiment ofthe heating device according to the invention.

FIG. 1 shows a part of a housing 1 of the heating device according tothe invention which consists of a rear wall 2 and two side walls 3.Formed together with a front wall, upper wall and lower wall (which arenot shown here) is a closed cabinet in which components of the heatingdevice are accommodated. Only heat exchanger 11 is shown here for thesake of clarity, although a heating module, a control unit and all therequired conduits are of course also accommodated in the cabinet.

According to the invention an insulating panel 4 is arranged againstrear wall 2 in order to increase the energy efficiency of the heatingdevice. This insulating panel 4 comprises a core material 12 enclosed bya foil 13 which is joined together at a seam 14 to forma gas and watervapour-tight packaging. A vacuum is created in the volume of thispackaging, whereby the heat conduction of core material 12 is greatlyreduced and the insulating action thus greatly increased. Core material12 can otherwise be formed by a pressed powder consisting substantiallyof microporous silicic acid. Cloaking means can also be present for thepurpose of minimizing the infrared radiation, as well as cellulosefibres for improving the mechanical stability. In the shown embodimentplastic foil 13 is a reflective foil. Because the vacuum-packed corematerial 12 insulates so well, panel 4 can have a small thickness of amaximum of several tens of millimetres. A panel with a thickness in theorder of a centimetre can probably suffice in practice.

In order to prevent damage to the insulating vacuum panel 4 as a resultof overheating, in the shown embodiment a spacer 5 is arranged betweenheat exchanger 11 and panel 4. This spacer 5 takes the form of a plate 6in which a number of relatively large openings 7 have been formed, sothat the spacer forms no obstruction to the heat radiation coming fromheat exchanger 11 and reflected by the reflective foil 13 of panel 4.The plate 6 forming the spacer 5 can have a considerably greaterthickness than vacuum panel 4; the thickness of plate 6 can be three toeight times that of panel 4. In the shown embodiment spacer 5 is aboutfive times as thick as panel 4.

Heat exchanger 11 is fixed to rear wall 2 by means of bolts 9 which arearranged on the rear wall and which protrude through eyes 10 on the edgeof heat exchanger 11. Openings 8 through which bolts 9 pass are alsoformed in spacer 5. In order to prevent openings having to be formed invacuum panel 4, which would make the construction of the panelconsiderably more difficult, the dimensions of vacuum panel 4 are chosensuch that it fits within the bolts 9. Panel 4 is simply enclosed herebetween wall 2 and spacer 5 so that no special provisions are requiredfor fixing thereof.

Another type of spacer can also be applied instead of the shownplate-like spacer 5 with large openings 7. In FIG. 3 the spacers areformed by simple bushes 15 round the bolts 9 with which heat exchanger11 is fixed to rear wall 2. Special provisions are indeed necessary hereto fix vacuum panel 4 to rear wall 2. As can be seen in the figure, thiscan for instance be realized by applying an adhesive layer 16 betweenpanel 4 and wall 2. It is also possible to envisage use being made ofspecial clamping brackets 17 for fixing purposes. What is important hereis that the fixing is such that foil 13 is not pierced, since theinsulating power of vacuum panel 4 would then be greatly reduced.

The application of an insulating material on the basis of avacuum-packed core material thus makes it possible to reduce the lossesof a heating device, particularly when it is not operational. The EnergyPerformance Coefficient of a building in which the heating device isapplied can hereby be reduced. In addition, comfort is hereby increasedsince the heating device more readily remains at temperature duringstandstill and can thereby bring the water more quickly to a desiredtemperature after being switched on.

Although the invention has been elucidated above on the basis of oneembodiment, it is not limited thereto. The vacuum-packed insulatingmaterial could thus also be applied at other locations in the heatingdevice. It is possible here to envisage the side walls, the upper andlower wall and parts of the front wall of the housing. The onlypractical limitation is that it is difficult to form passages throughthe vacuum-packed insulating material, so that it will not be possibleto insulate parts of the housing.

The scope of the invention is defined solely by the following claims.

1. Device for heating a flowing medium, wherein the device comprises aheating module and a heat exchanger at least partially enclosed by aninsulating material comprising a vacuum-packed core material.
 2. Deviceas claimed in claim 1, wherein the heating module and the heat exchangerare received in a housing having a number of walls, and wherein thevacuum-packed core material is arranged between at least one of thewalls and at least one of the heating module and the heat exchanger. 3.Device as claimed in claim 2, wherein the vacuum-packed core materialcomprises a panel arranged along at least one of the walls.
 4. Device asclaimed in claim 3, wherein the panel is arranged along a substantiallyclosed wall of the housing.
 5. Device as claimed in claim 1, wherein thevacuum-packed core material is at a distance from at least one of theheating module and the heat exchanger.
 6. Device as claimed in claim 3,further comprising at least one spacer arranged between the panel and atleast one of the heating module and the heat exchanger.
 7. Device asclaimed in claim 6, wherein the panel further comprises a reflectivefoil enclosing the vacuum-packed core material, and wherein the at leastone spacer is substantially permeable to radiation.
 8. Device as claimedin claim 7, wherein the at least one spacer comprises a plate with anumber of openings.
 9. Device as claimed in claim 6, wherein at leastone of the heating module and the heat exchanger is fixed with bolts toa wall of the housing, and the at least one spacer further comprises abush or ring arranged around at least one of the bolts.
 10. Device asclaimed in claim 1, wherein the flowing medium is water.
 11. Device asclaimed in claim 2, wherein the vacuum-packed core material is at adistance from at least one of the heating module and the heat exchanger.12. Device as claimed in claim 3, wherein the vacuum-packed corematerial is at a distance from at least one of the heating module andthe heat exchanger.
 13. Device as claimed in claim 4, wherein thevacuum-packed core material is at a distance from at least one of theheating module and the heat exchanger.
 14. Device as claimed in claim 4,further comprising at least one spacer arranged between the panel and atleast one of the heating module and the heat exchanger.
 15. Device asclaimed in claim 5, further comprising at least one spacer arrangedbetween the panel and at least one of the heating module and the heatexchanger.
 16. Device as claimed in claim 7, wherein at least one of theheating module and the heat exchanger is fixed with bolts to a wall ofthe housing, and the at least one spacer further comprises a bush orring arranged around at least one of the bolts.